Studies are to be caried out to develop a radoimmunoassay procedure for measuring metallothionein in biological fluids and tissues. The functional role of metallothionein in the etiology of cadmium-induced hypertension will also be investigated. Since metallothionein is induced in response to both cadmiun and mercury, the physicochemical properties of the protein produced in response to cadmium will be compared with those of the mercury-induced protein.